One of the light-emitting elements is an organic electroluminescent element (hereinafter, may be referred to as an organic EL element). The organic EL element is composed of, for example, a pair of electrodes (an anode and a cathode) and an organic light-emitting layer located between the pair of electrodes which are stacking on a substrate. When a voltage is applied to the organic EL element, holes are injected from the anode, and electrons are injected from the cathode. The holes and electrons are recombined in the organic light-emitting layer, and light is thereby emitted. In a so-called bottom emission-type organic EL element, the light emitted from the light-emitting layer is extracted to the outside through the substrate.
A large portion of the light emitted from the organic light-emitting layer is reflected from, for example, the surface of the substrate, and thus the light cannot be efficiently extracted from the organic EL element. In conventional technologies, for example, a number of microlenses are formed on the surface of the substrate to suppress the total reflection of light, and thereby the light extraction efficiency is improved (Patent Document 1).
Patent document 1: JP 2002-260854 A